So we get errors with older browsers.

So we can use it directly in lit-element templates and don't have to
add an event handler to window etc.

update() is called before the actual update so we need to change i18next there.

We now listen to our own signal so multiple language selects on the same page work
and are kept in sync.

Also use the same reference for removing the event handler, bind creates a new one.

So the default gitlab config keeps working